While humans are busy on the International Space Station learning about how the body behaves in space and carrying out experiments, their role is evolving to incorporate robotics more and more into their daily tasks.

Robots are getting smarter and humans are hoping that our mechanical friends will feature heavily in future space missions. Whether these robots are performing spacewalks or doing some heavy lifting, there are a variety of "helpers" aboard the orbiting outpost that are complementing our space flier's science. Here are some of the robots that have been and are being used on the space station.

SPHERES

The space station plays host to a small group of floating robots called SPHERES, which stands for Synchronized Position Hold Engage and Reorient Experimental Satellite. These bowling ball-sized drones can move in any direction (thanks to miniature carbon dioxide thrusters) and are useful for testing all sorts of technology, according to the European Space Agency. Shown here, NASA astronaut Tom Marshburn poses with one of the SPHERES' stereo cameras in 2012.

Just recently, ESA announced that one of the drones was able to judge distance using only one robotic eye. It's an impossible theoretical feat to perform. That said, if an object has been encountered many times, the robot can learn the shape and size of it over time.

"For this test, a drone began navigating inside Japan's module while recording stereo vision information from its two camera 'eyes'," ESA wrote in a statement. "It then began to learn about the distances to walls and nearby obstacles so that when its stereo camera was switched off, it could then begin autonomous exploration using only a single camera."

Kirobo

Kirobo was a small robot brought up to the ISS to address what the auto company Toyota sees as a growing problem in Japan: lonely seniors. The robot is able to sense your mood and have conversations based on what you are saying. The robot was flown to the space station in 2013, when it held conversations with Japanese astronaut Koichi Wakata (pictured above). The duo talked about many things, including the view from space and the robotic arm attached to the Japanese science module Kibo (more on that later).

While Kirobo hasn't been used in space for a while, development continues on the ground. Toyota recently released a "Kirobo Mini" small enough to sit in the palm of your hand. It's available for sale soon in Japan. The robot can charge in about three hours, and communicates for 2.5 hours continuously by looking at your face and voice to figure out your mood.

Robonaut 2

Robonaut 2 is a prototype of what could be a future helper for astronauts. The robot is designed to flip switches, turn knobs and do other simple tasks. While it's still in testing, the long-term aim is to let the robot do more simple tasks and to free up astronaut time for more complicated science experiments or procedures. The robot flew to the ISS in 2012 and was later upgraded with legs, processors and sensors to make it more able to do tasks.

"One advantage of a humanoid design is that Robonaut can take over simple, repetitive, or especially dangerous tasks on places such as the International Space Station. Because R2 is approaching human dexterity, tasks such as changing out an air filter can be performed without modifications to the existing design," NASA wrote on the Robonaut webpage.

"Another way this might be beneficial is during a robotic precursor mission. R2 would bring one set of tools for the precursor mission, such as setup and geologic investigation."

Dextre

Dextre is described as a "robotic handyman" that does work outside the space station, according to the Canadian Space Agency. It was launched in 2008 and is still in operation today, doing science experiments and complicated repairs.

One of the most dangerous operations astronauts undertake these days is to replace ammonia pumps on the space station. Dextre can help reduce the risk by doing the heavier maneuvering ahead of the astronauts putting the tank into place. In 2015, for example, Dextre removed a failed pump, grabbed a spare, and moved the spare to a spot where astronauts could easily install it.

Kibo

The Kibo robotic arm is part of the larger Japanese Experiment Module (which is itself nicknamed Kibo). This module has been in space since 2008, and was put together after several shuttle missions shipped it up in pieces. The arm is made up of a large, 10 meter-long robotic arm with the option to attach a "small fine arm" on the end effector of the main arm.

One prominent use of the Kibo robotic arm has been to help launch satellites from the space station (pictured here). It was first used on the station in 2012. It sits on the end of the Japanese robotic arm and allows for several small CubeSats to be sent aloft at one time. These CubeSats can be used for applications such as communications or Earth observations.